Medical device and method with improved biometric verification

ABSTRACT

The present invention is both a device and a method for verifying a subject&#39;s identity while using a medical device or undergoing a medical diagnostic or therapeutic procedure, particularly at home or at a remote location. The method and device can be used for inpatient and remote sleep and signal analysis with biometric identification. The present invention is further related to the devices and sensors used in executing the method, and includes various embodiments of a method of inpatient and remote sleep analysis.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/910,068, filed on Mar. 2, 2018, which is a continuation of U.S.patent application Ser. No. 14/173,897, filed on Feb. 6, 2014 and issuedas U.S. Pat. No. 9,943,252 on Apr. 17, 2018, which is a continuation ofU.S. patent application Ser. No. 12/228,461, filed on Aug. 13, 2008 andissued as U.S. Pat. No. 8,679,012 on Mar. 25, 2014.

BACKGROUND OF THE INVENTION 1. Field of Use

The present invention is both a device and a method for verifying asubject's identity while using a medical device or undergoing a medicaldiagnostic or therapeutic procedure, particularly at home or at a remotelocation.

2. Technology Review

Nearly one in seven people in the United States suffer from some type ofchronic sleep disorder, and only 50% of people are estimated to get therecommended seven to eight hours of sleep each night. It is furtherestimated that sleep deprivation and its associated medical and socialcosts (loss of productivity, industrial accidents, etc.) exceed $150billion per year. Excessive sleepiness can deteriorate the quality oflife and is a major cause of morbidity and mortality due to its role inindustrial and transportation accidents. Sleepiness further hasundesirable effects on motor vehicle operation, employment, higherearning and job promotion opportunities, education, recreation, andpersonal life.

Primary sleep disorders affect approximately 50 million Americans of allages and include narcolepsy, restless legs/periodic leg movement,insomnia, and most commonly, obstructive sleep apnea (OSA). OSA'sprevalence in society is comparable with diabetes, asthma, and thelifetime risk of colon cancer. OSA is grossly under diagnosed with anestimated 80-90% of persons afflicted having not received a clinicaldiagnosis. Secondary sleep disorders include loss of sleep due to painassociated with chronic infections, neurological/psychiatric disorders,or alcohol/substance abuse disorders.

Sleeping disorders are currently diagnosed by two general methods.Subjective methods, such as the Epworth and Standford Sleepiness Scale,generally involve questionnaires that require patients to answer aseries of qualitative questions regarding their sleepiness during theday. With these subjective methods, however, it is found that thepatients usually underestimate their level of sleepiness or theydeliberately falsify their responses because of their concern regardingpunitive action or as an effort to obtain restricted stimulantmedication.

The second group of methods uses a combination of sensors and variousphysiological measurements to examine a subject's sleep health. Anexample of such an approach is the use of all-night polysomnography(PSG) to evaluate a subject's sleep architecture (e.g., obtainingrespiratory disturbance index to diagnose sleep apnea). Sleep testing inthis manner typically requires patients to spend the night in a sleeplaboratory connected to multiple sensors while they attempt to sleep.Because it is conducted in a laboratory setting, sleep testing cannotprovide information about a patient's regular sleeping environment, suchas noise, light, or allergens. Sleep testing performed in a laboratorysetting can also be difficult to conduct because of a patient's travelconcerns or anxiety related to sleeping away from home. Many patientsalso exhibit a “first night effect” related to a change in sleepingenvironment. The first night effect often requires a second night in thesleep laboratory to obtain accurate results. Therefore, the first nighteffect can easily double the cost of conducting a sleep test in a sleeplaboratory. Further, these same problems and concerns are equallyapplicable to sleep therapeutic procedures conducted in a sleeplaboratory.

To address the difficulties of conducting sleep testing and therapy in asleep laboratory, various methods and devices have been developed toperform remote sleep testing and/or therapy from a subject's regularsleeping location. Currently, methods and devices exist which allowremote sleep testing and therapy to be performed using either a remotelyattended study or a remote unattended study. In a remotely attendedsleep test or therapeutic procedure, data from various sensors istransmitted from the study site to a remote site for analysis inreal-time or near real-time. Data transmitted not only includes sleepsensor measurements, but can also include audio and video data, allowinga remote attendant to visually and/or audibly monitor a sleep study inaddition to monitoring standard physiological parameters. In unattendedremote sleep tests or therapeutic procedures, data from various sleepsensors is simply stored during the sleep test and analyzed by a medicalprofessional at a later time.

The use of remote sleep testing and therapy has many advantages,including alleviation of first night effect, and reduction of cost andinconvenience associated with a subject's being required to travel to asleep laboratory to undergo these procedures. For these reasons andothers, remote sleep testing and therapy has grown significantly inrecent times and is likely to continue to increase in prevalence as itbecomes more reliable and as understanding of the importance of sleephealth continues to increase.

One area of concern associated with the increasing use of unattendedremote sleep studies is that of ensuring that the subject for whom asleep study was intended, is the subject from whom sleep data was infact collected. Various reasons exist for a subject to falsify sleeptest data by having another individual undergo sleep testing in his orher place. Among the most compelling reasons are fear of lifestylechange, fear of possible punitive action and fear that one's employmentor means of support may be affected by a positive diagnosis for a sleepdisorder. The temptation to falsify sleep test results is of specialconcern among individuals performing sleep-critical jobs such asover-the-road truck drivers, airline pilots and others similarlyemployed. Not only are there strong reasons for these individuals tofalsify sleep test results because of possible effects on job stability,but the danger posed both to themselves and others such as airlinepassengers and other drivers is significant.

One method of addressing this concern is to incorporate a subjectidentification process into the sleep testing procedure. Such a stepwould serve to ensure that sleep test data is in fact collected from theindividual for whom the sleep test was intended. Currently, none of themethods or devices used for unattended remote sleep testing and therapyprovide means for verification of patient identity during a sleepdiagnostic or therapeutic procedure. Further, none of the methods ordevices presently used for sleep testing and sleep therapy performed ina sleep laboratory or performed using remote attendance provide meansfor simple, secure, biometric verification of subject identity.

It is therefore an object of the present invention to provide a methodand device for conducting biometric verification of subject identity aspart of unattended remote sleep testing and sleep therapy procedures. Itis another object of the present invention to provide a method or devicefor conducting biometric verification of subject identity as part ofsleep testing and sleep therapy procedures conducted in a sleeplaboratory as well as sleep testing and sleep therapy procedures whichare remotely attended. It is still another object of the presentinvention to provide a method or device by which biometricidentification of a sleep test subject or sleep therapy subject can beperformed using a portable sleep diagnostic and/or therapeutic systemwhile the subject sleeps. It is another object of the present inventionto provide a method or device for securely handling biometric data incompliance with HIPAA and HCFA standards. It is another object of thepresent invention to provide a method or device for coordinating thestep of biometric verification of a subject's identity with variousphysical or physiological parameters measured from the subject. It isstill another object of the present invention to provide a method ordevice for coordinating biometric verification of subject identity withsleep onset during sleep testing. Still another object of the presentinvention is to provide correlation between biometric verification ofsubject identity and heart rate measured using both ECG and pulseoximetry to ensure that a subject for whom a sleep test was intended isthe subject from whom test measurements were acquired.

SUMMARY OF THE INVENTION

The present invention is both a device and a method for verifying asubject's identity while using a medical device or undergoing a medicaldiagnostic or therapeutic procedure, particularly at home or at a remotelocation. The method and device can be used for inpatient and remotesleep and signal analysis with biometric identification. The presentinvention is further related to the devices and sensors used inexecuting the method, and includes various embodiments of a method ofinpatient and remote sleep analysis.

The device and method of the present invention is particularly useful ina number of applications. These applications include but are not limitedto conducting sleep analysis wherein verification of subject identityduring the sleep analysis procedure is necessary. Some of theapplications for example include but are not limited to testing of truckdrivers, airline pilots, automobile drivers, other sleep critical jobsand the like. The device and method of the present invention isparticularly useful when remotely testing a subject with a sleepingdisorder, more particularly obstructive sleep apnea. The device andmethod of the present invention includes any useful applications, whichwill be apparent to those skilled in the art.

The device and method of the present invention prevents misuse or fraudwhen using the invention to test a subject, ensuring that the subjectbeing tested is in fact the subject for whom the test was intended.Numerous methods are disclosed to prevent the subject from misleading aclinician or doctor. Among the methods disclosed is the use of biometricparameters to verify a subject's identity. Biometric parameters forexample include fingerprints, voice, physiological information, retinalscan, palm recognition, and the like. Also disclosed are methods ofpreventing misuse or fraud when testing a subject, which include random,periodic or continuous biometric verification of subject identity duringa test. Other methods disclosed in the present invention includecorrelation of physiologic parameters pertaining to a subject's sleepquality or the time of sleep onset with the step of biometricverification. Still other methods exist, many of which will be clearcombinations of the steps disclosed herein.

The device and method of the present invention further provides forsecure handling of a subject's biometric and medical information. Tothis end, the device and method of the present invention includes meanswhereby biometric data can be temporarily stored, easily erased, and notcommunicated other devices. Further provisions of the present inventionto ensure secure handling of a subject's biometric and medical datainclude the use of HIPAA and HCFA compliant transfer of such data forapplications in which transfer of such data is necessary or desired.

Examples of various embodiments of the present invention are as follows.In one embodiment, the present invention includes a sleep diagnosticdevice comprising at least three sensors for measuring physiologicalparameters of a subject related to the subject's quality of sleep and atleast one biometric sensor for identifying the subject wherein the atleast one biometric sensor is used to authenticate the identity of thesubject being tested.

In another embodiment, the present invention includes a sleep diagnosticdevice comprising at least three sensors for measuring physiologicalparameters of a subject related to the subject's quality of sleep, oneof the at least three sensors used to measure airflow from a nasalcanula, and at least one biometric sensor for identifying the subjectwherein the at least one biometric sensor is used to authenticate theidentity of the subject being tested.

In still another embodiment, the present invention includes a sleepdiagnostic device comprising at least four sensors for measuringphysiological parameters of a subject related to the subject's qualityof sleep wherein the at least four sensors for measuring physiologicalparameters are used to measure ventilation, respiratory effort, ECG orheart rate, and blood oxygen saturation and at least one biometricsensor wherein the at least one biometric sensor is used to authenticatethe identity of the subject being tested.

In even another embodiment, the present invention includes a sleepdiagnostic device comprising at least seven sensors for measuringphysiological parameters of a subject related to the subject's qualityof sleep wherein the at least seven sensors for measuring physiologicalparameters are used to measure ventilation, respiratory effort, ECG orheart rate, blood oxygen saturation, EEG, EOG, and EMG and at least onebiometric sensor wherein the at least one biometric sensor is used toauthenticate the identity of the subject being tested.

In even still another embodiment, the present invention includes a sleepdiagnostic device comprising at least one sensor for measuringphysiological parameters of a subject related to the subject's qualityof sleep, at least one biometric sensor for identifying the subject, anda processor wherein the at least one biometric sensor is used to collectbiometric data, the processor compares the collected biometric data withbiometric data previously collected from the subject, and the processoroutputs verification of the identity of the subject whose quality ofsleep is being measured without outputting the subject's biometric data.

In even still another embodiment, the present invention includes a sleepdiagnostic device comprising at least one sensor for measuringphysiological parameters of a subject related to the subject's qualityof sleep and at least one biometric sensor for identifying the subjectwherein the sleep diagnostic device is used to collect biometric data,compare biometric data with previously collected biometric data, andsecurely exchange information with an external device.

In still yet another embodiment, the present invention includescoordinating the step of biometric verification of subject identity withvarious physical and physiological parameters as measured by the varioussensors used with the present invention.

In still yet another embodiment, the present invention includes a methodof performing sleep analysis or diagnosis comprising the steps ofmeasuring at least one physiological parameter related to the quality ofa subject's sleep, determining a sleep onset time for the subject basedat least in part on the at least one physiological parameter, measuringat least one biometric parameter of the subject about the sleep onsettime of the subject, and comparing the measured at least one biometricparameter of the subject to previously obtained biometric data of thesubject.

In still yet another embodiment, the present invention includes a methodof performing sleep analysis or diagnosis of a sleep disorder comprisingthe steps of coordinating heart rate as measured with ECG electrodes andheart rate measured using pulse oximetry in combination with biometricidentification to further ensure that a subject for whom a sleep testwas intended is the subject from whom sleep test data was collected.

In still yet another embodiment, the present invention includes a methodof performing sleep analysis or diagnosis comprising the steps ofmeasuring at least one physiological parameter related to the quality ofa subject's sleep, determining a sleep onset time for the subject basedat least in part on the at least one physiological parameter, measuringat least one biometric parameter of the subject, and comparing themeasured at least one biometric parameter of the subject to previouslyobtained biometric data of the subject wherein the subject's quality ofsleep is measured for at least two hours after the sleep onset time ofthe subject.

Additional features and advantages of the invention will be set forth inthe detailed description that follows, and in part will be readilyapparent to those skilled in the art from that description or recognizedby practicing the invention as described herein, including the detaileddescription that follows, the claims, as well as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description are merely exemplary of theinvention, and are intended to provide an overview or framework forunderstanding the nature and character of the invention as it isclaimed. The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate various embodimentsof the invention and, together with the description, serve to explainthe principles and operation of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 Schematic diagram of a subject using one embodiment of themedical device and/or method with improved biometric verification.

FIG. 2 Schematic diagram of the data transfer and sharing devices and/orprocesses of one embodiment of the medical device and method withimproved biometric verification.

FIG. 3 Block diagram of the data acquisition system of one embodiment ofthe present invention.

FIG. 4 Block diagram of the biometric sensing device showing thecollection and flow of biometric data as it occurs in one embodiment ofthe present invention.

FIG. 5 Flow diagram of one embodiment of the method of biometricverification of identity used in the present invention.

FIGS. 6A-D Perspective views of various embodiments of the applicationsof the sensors of medical device and method with improved biometricverification of the present invention.

FIG. 7 Flow diagram of an embodiment illustrating a specificoccupation-based application of the medical device and method withimproved biometric verification.

FIG. 8 Flow diagram of another embodiment illustrating a specificoccupation-based application of the medical device and method withimproved biometric verification.

FIG. 9 Block diagram illustrating the data acquisition and data handlingdevice and processes used in one embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is related to both a method and device forverifying a subject's identity while using a medical device orundergoing a medical diagnostic or therapeutic procedure. The presentinvention is further related to the devices and sensors used inexecuting the method and includes, but is not limited to, variousembodiments of a method and device used to verify a subject's identityand perform inpatient and remote sleep testing and analysis. Althoughthe various embodiments described below primarily include a method anddevice for sleep analysis, it is not intended that the present inventionbe limited to such applications. Various other embodiments of thepresent invention using other medical devices will be apparent to thoseskilled in the art. Examples of such other embodiments include, but arenot limited to, the use of other devices such as blood alcohol levelsensors, heart rate monitors, sleep therapeutic devices, oxygensaturation devices, pharmaceutical delivery devices and various othermedical diagnostic and therapeutic devices.

Various embodiments of the present invention may include a step fordetermining whether the subject being analyzed for a sleep disordermaintained a normal sleeping pattern prior to the analysis. This stepcan be performed or accomplished a number of ways. In the simplest form,the subject can be questioned regarding his or her previous sleeppatterns. In a somewhat more complex form the subject can be requestedto fill out a questionnaire, which then can be graded to determinewhether his or her previous sleep patterns where normal (or appearednormal). In an even more complex form the subject might undergo allnight polysomnography to evaluate the subject's sleep architecture(e.g., obtaining respiratory disturbance index to diagnose sleep apnea).One of the objectives of this step is to ensure that the results of thesubject's brain wave analysis are not the result of or affected by thesubject's previous environmental factors i.e., intentional lack ofsleep, etc. It is clear that there are numerous ways beyond thoseexamples previously mentioned of determining whether the subject beinganalyzed maintained or thought they were maintaining a normal sleepingpattern prior to analysis, therefore the examples given above areincluded as exemplary rather than as a limitation, and those ways ofdetermining whether the subject maintained or thought they weremaintaining a normal sleeping pattern known to those skilled in the artare considered to be included in the present invention.

Various embodiments of the present invention may include the step ofconducting an inpatient or remote sleep analysis that is attended from aremote location. Such remote attendance can be accomplished by anindividual in a remote location (a remote monitor) periodically orcontinuously viewing the data transmitted from the remote or in-homedata acquisition system, including signals from the sensors applied tothe subject including biometric signals, signals from the environmentalsensors, and a pre-processed signal or signals based at least in part onat least one of the sensors. Preferably, the remote monitor is capableof communicating with the subject, subject's assistant, or otherindividual near the subject. Such communication allows the remotemonitor to provide instructions to the subject, subject's assistant, orother individual near the subject, for example, to adjust a sensor,close window blinds, remove a source of noise, or wake the subject. Morepreferably, the remote monitor is capable of two-way communication withthe subject, subject's assistant, or other individual near the subject.Such communication allows the subject, subject's assistant, or otherindividual close to the subject to ask the remote monitor questions, forexample, to clarify instructions. Depending on the setting for the testthis other individual may be a nurse or trained technician at thehospital, nursing home or skilled medical facility. In other settings,it may be any other individual trained in the placement and hookup ofthe sensors. In still other settings, it might be the subject themselveswho could be directed by the monitor as to sensor adjustment, placementand hookup.

Various embodiments of the present invention include an interface boxwhich is preferably used to protect one or more electrical componentsand allow for the connection of various sensors to the electricalcomponents inside the interface box. The interface box is preferably issecured to or held by the subject. The box also preferably haselectrical connectors incorporated in to its structure, so that varioussensors can be connected to the box and through to the electricalcomponents inside the interface box. Preferably the connectorsincorporated into the interface box are no touch connectors which enableconnections to commercially available electrodes and sensors. Theinterface box preferably has at least one air port connection to one ormore internal sensors, such as one or more pressure transducers or othersensors. The interface box more preferably has at least two air portconnections to one or more internal sensors, such as one or morepressure transducers or other sensors. The interface box can beconstructed from most any rigid material; including, but not limited to,various types of wood, various types of plastics, various types ofpolymers, various types of resin, various types of ceramics, varioustypes of metals, and various types of composite materials. Preferablythe box is constructed of an electrically insulative and light weightmaterial such as a type of plastic, rigid polymer, fiberglass, carbonfiber composite, or other material with similar characteristics.

Various embodiments of the present invention may include the step ofapplying one or more sensors to the subject. Preferably at least threesensors are applied to the subject, more preferably at least 4, stillmore preferably at least five sensors, even more preferably at least 7,most preferably at least 9. The sensors can be applied at a variety oflocations. Preferably, the sensors are applied in a physician's officeor at a place of business. The physician's place of business includesbut is not limited to an office building, a freestanding clinic,location within a hospital, mobile vehicle or trailer, leased space, orsimilar location. Just as preferably, the sensors could be applied inthe subject's home or other sleeping location. The subject's sleepinglocation includes but is not limited to the subject's home, apartment,and the like, as well as a hotel, nursing facility, or other locationwhere an individual could sleep and where this analysis could be donemore controllably and/or less expensively than in a sleep lab orhospital setting. Similarly, the sensors can be applied by a variety ofindividuals, including but not limited to a physician, nurse, sleeptechnician, or other healthcare professional. Just as preferably, thesensors could be applied by the subject or the subject's spouse, friend,roommate, or other individual capable of attaching the various sensors.More preferably, the sensors could be applied by the subject or thesubject's spouse, friend, roommate, or other individual capable ofattaching the various sensors with guidance and instruction. Suchguidance and instruction can include static information such aspamphlets, audio recordings (on cassettes, compact discs, and the like),video recordings (on videocassettes, digital video discs, and the like),websites, and the like, as well as dynamic information such as directreal-time communication via telephone, cell phone, videoconference, andthe like.

The sensors that are used with various embodiments of the presentinvention are described herein but can also be any of those known tothose skilled in the art for the applications of this method. Thecollected physiological, kinetic, environmental, and biometric data fromthe sensors can be obtained by any method known in the art. Preferablythose sensors include, but are not limited to, wet or dry electrodes,photodetectors, accelerometers, pneumotachometers, strain gauges,thermal sensors, pH sensors, chemical sensors, gas sensors (such asoxygen and carbon dioxide sensors), transducers, piezo sensors,magnetometers, pressure sensors, static charge-sensitive beds,microphones, audio monitors, video monitors, fingerprint sensors, facialrecognition sensors, hand geometry sensors iris and retinal sensors,voice recognition sensors and the like. The invention is envisioned toinclude those sensors subsequently developed by those skilled in the artto detect these types of signals as well. For example, the sensors canbe magnetic sensors. Because electro-physiological signals are, ingeneral, electrical currents that produce associated magnetic fields,the present invention further anticipates methods of sensing thosemagnetic fields to acquire the signal. For example, new magnetic sensorscould collect brain wave signals similar to those that can be obtainedthrough a traditional electrode applied to the subject's scalp.

Various embodiments of the present invention include a step for applyingsensors to the subject. This step can be performed or accomplished in anumber of ways. In the preferred form, four sensors are applied to thesubject to measure three channels of physiologic data, and one channelof biometric data. In a somewhat more complex form, multiple sensors areapplied to the subject to collect data sufficient for a fullpolysomnography (PSG) test. The preferred set of sensors for PSG testingincludes sensors for two electroencephalogram (EEG) channels, two(electrooculogram) EOG channels, one chin electromyogram (EMG) channel,one nasal airflow channel, one oral airflow channel, oneelectrocardiogram (ECG) channel, one thoracic respiratory effortchannel, one abdominal respiratory effort channel, one pulse oximetrychannel, and one shin or leg EMG channel. More preferably, the minimalset of PSG sensors is augmented with at least one additional channel ofEOG, one channel of body position (ex., an accelerometer), one channelof video, and optionally one channel of audio. In an even more complexform, many sensors are applied to the subject to collect full PSG dataas well as additional physiological, kinetic, and environmental data.For example, additional EEG electrodes may be applied to the subject torule out seizure disorders, an esophageal pH sensor may be used todetect acid reflux, and a hygrometer or photometer may be used to detectambient humidity or light, respectively.

Electro-physiological signals such as those obtained via EEG, ECG, EMG,EOG, electroneurogram (ENG), electroretinogram (ERG), and the like canbe collected via electrodes placed at one or several relevant locationson the subject's body. For example, when measuring brain wave or EEGsignals, electrodes may be placed at one or several locations on thesubject's scalp. In order to obtain a good electro-physiological signal,it is desirable to have low impedances for the electrodes. Typicalelectrodes placed on the skin may have an impedance in the range of from5 to 10 kΩ. It is in generally desirable to reduce such impedance levelsto below 2 kΩ. A conductive paste or gel may be applied to the electrodeto create a connection with an impedance below 2 kΩ. Alternatively or inconjunction with the conductive gel, a subject's skin may bemechanically abraded, the electrode may be amplified, or a dry electrodemay be used. Dry physiological recording electrodes of the typedescribed in U.S. Pat. No. 7,032,301 are herein incorporated byreference. Dry electrodes are advantageous because they use no gel thatcan dry out, skin abrasion or cleaning is unnecessary, and the electrodecan be applied in hairy areas such as the scalp. Additionally ifelectrodes are used as the sensors, preferably at least two electrodesare used for each channel of data—one signal electrode and one referenceelectrode. Optionally, a single reference electrode may be used for morethan one channel.

If electrodes are used to collect cardiac electrical signals such as inan ECG, they may be placed at specific points on the subject's body. TheECG is used to measure the rate and regularity of heartbeats, determinethe size and position of the heart chambers assess any damage to theheart, and diagnose sleeping disorders. An ECG is important as a tool todetect the cardiac abnormalities that can be associated with sleep andrespiratory-related disorders. Although a full ECG typically involvestwelve electrodes, only two are required for many tests such as a sleepstudy. For example, when two electrodes are used to collect an ECG,preferably one is placed on the subject's left-hand ribcage under thearmpit, and the other preferably on the right-hand shoulder near theclavicle bone. Optionally, a full set of twelve ECG electrodes may beused, such as if the subject is suspected to have a cardiac disorder.The specific location of each electrode on a subject's body is wellknown to those skilled in the art and varies between both individualsand types of subjects. If electrodes are used to collect ECG data,preferably the electrode leads are connected to a device contained inthe signal processing module of the data acquisition system used in thepresent invention that measures potential differences between selectedelectrodes to produce ECG tracings.

Other sensors can be used to measure various parameters of a subject'srespiration. Measurement of respiratory airflow is preferably performedusing sensors or devices such as a pneumotachometer, strain gauges,thermal sensors, transducers, piezo sensors, magnetometers, pressuresensors, static charge-sensitive beds, pulse oximeters and the like.These sensors or devices also preferably measure nasal pressure,respiratory inductance plethysmography, thoracic impedance, expiredcarbon dioxide, tracheal sound, snore sound, blood pressure and thelike. Measurement of respiratory effort is preferably measured by arespiration belt, esophageal pressure, surface diaphragmatic EMG, andthe like. Measurement of oxygenation and ventilation is preferablymeasured by pulse oximetry, transcutaneous oxygen monitoring,transcutaneous carbon dioxide monitoring, expired end carbon dioxidemonitoring, and the like.

One example of such a sensor for measuring respirations either directlyor indirectly is a respiration belt. Respiration belts can be used tomeasure a subject's abdominal and/or thoracic expansion over ameasurement time period. The respiration belts may contain a straingauge, a pressure transducer, or other sensors that can indirectlymeasure a subject's respirations and the variability of respirations byproviding a signal that correlates to the thoracic/abdominalexpansion/contraction of the subject's thoracic/abdominal cavity. Ifrespiration belts are used, they may be placed at one of severallocations on the subject's torso or in any other manner known to thoseskilled in the art. Preferably, when respiration belts are used, theyare positioned below the axilla and/or at the level of the umbilicus tomeasure rib cage and abdominal excursions. More preferably, at least twobelts are used, with one positioned at the axilla and the other at theumbilicus.

Another example of a sensor or method for measuring respirations eitherdirectly or indirectly is a nasal cannula or a facemask used to measurethe subject's respiratory airflow. Nasal or oral airflow can be measuredquantitatively and directly with a pneumotachograph consisting of apressure transducer connected to either a standard oxygen nasal cannulaplaced in the nose or a facemask over the subject's mouth and nose.Airflow can be estimated by measuring nasal or oral airway pressure thatdecreases during inspiration and increases during expiration.Inspiration and expiration produce fluctuations on the pressuretransducer's signal that is proportional to airflow. A single pressuretransducer can be used to measure the combined oral and nasal airflow.Alternatively, the oral and nasal components of these measurements canbe acquired directly through the use of at least two pressuretransducers, one transducer for each component. Preferably, the pressuretransducer(s) are internal to the interface box. If two transducers areused for nasal and oral measurements, preferably each has a separate airport into the interface box. In addition, software filtering can obtain“snore signals” from a single pressure transducer signal by extractingthe high frequency portion of the transducer signal. This methodeliminates the need for a separate sensor, such as a microphone or anadditional pressure transducer, and also reduces the system resourcesrequired to detect both snore and airflow. A modified nasal cannula orfacemask connected to a carbon dioxide or oxygen sensor may also be usedto measure respective concentrations of these gases. In addition, avariety of other sensors can be connected with either a nasal cannula orfacemask to measure a subject's respirations either directly orindirectly.

Still another example of a sensor or method of directly or indirectlymeasuring respiration of the subject is a pulse oximeter. The pulseoximeter can measure the oxygenation of the subject's blood by producinga source of light at two wavelengths (650 nm and 905, 910, or 940 nm).Hemoglobin partially absorbs the light by amounts that differ dependingon whether it is saturated or desaturated with oxygen. Calculating theabsorption at the two wavelengths leads to an estimate of the proportionof oxygenated hemoglobin. Preferably, pulse oximeters are placed on asubject's earlobe or fingertip. More preferably, the pulse oximeter isplaced on the subject's index finger. In one embodiment of the presentinvention, a pulse oximeter is built-in or hard-wired to the interfacebox. Alternatively, the pulse oximeter can be a separate unit incommunication with the interface box via either a wired or wirelessconnection.

Other sensors can be used to measure various parameters associated withthe subject's movement and posture. For example, kinetic data can beobtained by accelerometers placed on the subject. Alternatively, severalaccelerometers can be placed in various locations on the subject, forexample on the wrists, torso, and legs. These accelerometers can provideboth motion and general position/orientation data by measuring gravity.A video signal can also provide some kinetic data after processing.Alternatively, stereo video signals can provide three-dimensionalposition and motion information. Kinetic data includes but is notlimited to frequent tossing and turning indicative of an unsuitablemattress, excessive movement of bedding indicating unsuitable sleepingtemperatures, and unusual movement patterns indicating pain. Inaddition, gyroscopic sensors and the like may also be used.

Environmental data can be collected by video cameras, microphones (todetect noise level, etc.), photodetectors, light meters, thermalsensors, particle detectors, chemical sensors, mold sensors, olfactorysensors, barometers, hygrometers, and the like. Environmental data canprovide insight into the subject's sleeping location and habits that isunavailable in the traditional laboratory setting. Environmental datacan indicate that the subject's sleeping location is a potential sourceof the subject's sleeping difficulty. By way of example, but notlimitation, environmental data can indicate that the subject's sleepinglocation has an unsuitable temperature, humidity, light level, noiselevel, or air quality. For example, these environmental conditions cancause sweating, shivering, sneezing, coughing, noise, and/or motion thatdisrupts the patient's sleep. The environmental sensors can be placedanywhere in the subject's sleeping location or on the subject, ifappropriate. Preferably, the environmental sensors are placed near, butnot necessarily on, the subject.

Other sensors or devices can be used to measure and collect datapertaining to a subject's unique physical traits or biometriccharacteristics. This data can then be used for positive identificationof a subject during a medical or therapeutic procedure, and inparticular during sleep diagnosis and/or therapy. This data ispreferably collected using sensors or devices capable of recordingbiometric parameters such as hand geometry, vein morphology,fingerprints, DNA characteristics, facial and voice characteristics,iris and retinal characteristics and the like.

One example of such a sensor for measuring a biometric parameter is thefingerprint sensor. The use of fingerprints is a desirable approach tobiometric identification in medical and therapeutic applications, and inparticular during sleep diagnosis and/or therapy applications becausefingerprints are permanent, highly unique, universal and easilycollectable. Fingerprints are unique, in part, due to the randomvariations in fingerprint ridges which lead to formation of other uniquefeatures known as minutiae. Examples of minutiae include, but are notlimited to, ridge bifurcation, ridge trifurcation, ridge endings, andridge spurs. Establishment of fingerprint identity is accomplished byrecording the location and orientation of a number of these minutiae.Once this information has been recorded and stored, an individual can besubsequently identified by the system by comparison of the newlycollected fingerprint data with previously recorded fingerprint data.

Fingerprint sensors employ various methods to collect information usedto identify a subject including capacitive, optical, thermal andultrasonic methods. After data collection, advanced algorithms can beused to isolate and extract the unique features of the fingerprint inorder to positively identify a previously identified subject bycomparison with existing fingerprint data. One embodiment of the presentinvention includes the use of at least one fingerprint sensor to providepatient identification during the course of a remote sleep test.Preferably this fingerprint sensor is of the capacitive type. Thefingerprint sensor could be integrated into the finger-gripping portionof the pulse oximeter, allowing fingerprint sensing to occur on the samefinger as pulse oximetry. Optionally, the fingerprint sensor could beconnected to the pulse oximeter in such a way as to allow fingerprintanalysis of the finger immediately adjacent to the pulse oximeter.Further optionally, the fingerprint sensor could be attached to thepulse oximeter in such a way that it is independent of the pulseoximeter yet requires use of the fingerprint sensor on the same hand asthe pulse oximeter. Still further optionally, fingerprint identificationcould be performed on multiple fingers using multiple fingerprintsensors used independently of, or in combination with, other sensors.

To ensure patient compliance/authentication for the duration of sleepanalysis testing, it is preferable that one or more biometric parametersbe verified during the course of a sleep test. For example, a simple,non-invasive fingerprint scan using one of the embodiments describedabove could be performed continuously, randomly or at periodic intervalsduring the course of the sleep test to ensure that the individual beingtested is the individual for whom the test was intended. Additionally,the step of biometric verification of subject identity could becoordinated with measurements from various other physiologic sensorsused in the present invention in order to further ensure that collectedtest data are recorded from the intended test subject. An example ofthis approach is the use of blood oxygen saturation as measured by apulse oximeter to detect sleep onset and, shortly after detection ofsleep onset, conducting biometric verification of subject identity.Another example of this approach could include correlation of heart rateas measured by ECG electrodes placed on the subject with heart rate asmeasured using a pulse oximeter in combination with biometricverification of subject identity. In this example, correlation of heartrate as measured by two different sensors in combination with biometricverification prevents a subject from falsifying certain aspects of thesleep test by placing ECG sensors on a different individual whilewearing the pulse oximeter and biometric sensing device. In still otherexamples, various forms of plethysmography could be correlated with thestep of biometric identification to ensure subject compliance with thesleep test. Still many other methods and combinations of coordinatingand/or correlating the step of biometric identification with physicaland physiological parameters exist and will be apparent to those skilledin the art and the examples above are not intended to limit the presentinvention.

Because of the sensitive nature of biometric data, it is preferable tocollect, maintain and handle this data in a secure and reliable fashion,and in a method that is compatible with HIPAA and HCFA guidelines. Inone embodiment of the present invention, the biometric data used toverify subject identity during the course of a sleep test is obtaineddirectly from the subject in the presence of one who can verify thesubject's identity using standard methods prior to collection ofbiometric data. In still another embodiment of the present invention,biometric data can be loaded into the biometric sensor or device from apreexisting data source such as an employee or patient file, or thelike. Still other methods exist for acquiring biometric data (e.g. viaremote upload), and the present invention is not limited to thosemethods described above.

Once collected, biometric data can be handled and processed in a varietyof ways. In one embodiment of the present invention, biometric data iscollected from a biometric sensor or sensors and exported to a dataacquisition system where it is processed for use in subjectauthentication during sleep testing. Optionally, this data could befurther sent to a remote location for additional processing or storagefor use in future applications. In another embodiment, biometric data iscollected from a biometric sensor or sensors and data processing andpatient authentication occur within the body of the biometric sensor orthe data acquisition device. In this embodiment, sensitive biometricdata is not exported to a new location, rather a simple pass/fail resultfor the authentication test is the only data exported. An advantage ofthis approach is greater biometric data security, as biometric datawould not leave the biometric sensor and could be easily overwritten.Further, such an approach may also alleviate subjects' fears associatedwith collection of such uniquely identifiable data.

Various embodiments of the present invention include the step ofconnecting the applied sensors to a data acquisition system. The sensorscan be connected to the data acquisition system either before or afterthey are applied to the subject. As an example of connecting the sensorsto the data acquisition system after the sensors are applied to thesubject, a physician can apply the sensors to the subject and then sendthe subject home. While at home, the subject can connect the appliedsensors to the data acquisition system. Alternatively, the sensors canbe connected to the data acquisition system and then applied to thesubject.

The sensors can alternatively be permanently hardwired to at least partof the data acquisition system. More preferably, the sensors areconnected to at least part of the data acquisition system via releasableconnector. The physiological sensors are generally hardwired(permanently or via releasable connector) to the data acquisitionsystem, but the ongoing evolution in wireless sensor technology mayallow sensors to contain wireless transmitters. Optionally, such sensorsare wirelessly connected to the data acquisition system. As such, thesesensors and the wireless connection method are considered to be part ofthe present invention. With the advances in microelectromechanicalsystems (MEMS) sensor technology, the sensors may have integrated analogamplification, integrated A/D converters, and integrated memory cellsfor calibration, allowing for some signal conditioning directly on thesensor before transmission.

Preferably, the sensors are all connected in the same way at the sametime, although this is certainly not required. It is possible, but lesspreferable, to connect the sensors with a combination of methods (i.e.,hardwired or wireless) at a combination of times (i.e., some beforeapplication to the subject, and some after application to the subject).

Various embodiments of the present invention use a data acquisitionsystem. The data acquisition system is preferably portable. By portable,it is meant, among other things, that the device is capable of beingtransported relatively easily. Relative ease in transport means that thedevice is easily worn and carried, generally in a carrying case, to thepoint of use or application and then worn by the subject withoutsignificantly affecting any range of motion. Furthermore, any componentsof the data acquisition system that are attached to or worn by thesubject, such as the sensors and patient interface box, should also belightweight. Preferably, these patient-contacting components of thedevice (including the sensors and the patient interface box) weigh lessthan about 10 lbs., more preferably less than about 7.5 lbs., even morepreferably less than about 5 lbs., and most preferably less than about2.5 lbs. Thus, the patient-contacting components of the devicepreferably are battery-powered and use a data storage memory card and/orwireless transmission of data, allowing the subject to be untethered.Furthermore, the entire data acquisition system (including thepatient-contacting components as well as any environmental sensors, basestation, or other components) preferably should be relativelylightweight. By relatively lightweight, it is meant preferably theentire data acquisition system, including all components such as anyprocessors, computers, video screens, cameras, and the like preferablyweigh less in total than about 20 lbs., more preferably less than about15 lbs., and most preferably less than about 10 lbs. This dataacquisition system preferably can fit in a reasonably sized carryingcase so the patient or assistant can easily transport the system. Bybeing lightweight and compact, the device should gain greater acceptancefor use by the subject.

While the equipment and methods used in the various embodiments of thepresent invention can be used in rooms or buildings adjacent to thesubject's sleeping location, due to the equipment's robust nature thesemethods are preferably performed over greater distances. Preferably, thesubject's sleeping location and the remote locations, for example thelocation of the remote monitor, are separate buildings. Preferably, thesubject's sleeping location is at least 1 mile from the remotelocation(s) receiving the data; more preferably, the subject's sleepinglocation is at least 5 miles from the remote location(s) receiving thedata; even more preferably, the subject's sleeping location is at leasttwenty miles from the remote location(s) receiving the data; still morepreferably, the subject's sleeping location is at least fifty miles fromthe remote location(s) receiving the data; still even more preferably,the subject's sleeping location is at least two hundred-fifty miles fromthe remote location(s) receiving the data; more preferably, thesubject's sleeping location is in a different state from the remotelocation(s) receiving the data; and most preferably, the subject'ssleeping location is in a different country from the remote location(s)receiving the data.

Various embodiments of the present invention use a data acquisitionsystem capable of receiving signals from the sensors applied to thesubject and capable of retransmitting the signals or transmittinganother signal based at least in part on at least one of the signals. Inits simplest form, the data acquisition system preferably shouldinterface with the sensors applied to the subject and retransmit thesignals from the sensors. Preferably, the data acquisition systemwirelessly transmits the signals from the sensors. Optionally, the dataacquisition system also pre-processes the signals from the sensors andtransmits the pre-processed signals. Further optionally, the dataacquisition is also capable of storing the signals from the sensorsand/or any pre-processed signals.

Various embodiments of the present invention use a data acquisitionsystem capable of storing and/or retransmitting the signals from thesensors or storing and/or transmitting another signal based at least inpart on at least one of the signals. The data acquisition system can beprogrammed to send all signal data to the removable memory, to transmitall data, or to both transmit all data and send a copy of the data tothe removable memory. When the data acquisition system is programmed tostore a signal or pre-processed signal, the signals from the sensors canbe saved on a medium in order to be retrieved and analyzed at a laterdate. Media on which data can be saved include, but are not limited tochart recorders, hard drive, floppy disks, computer networks, opticalstorage, solid-state memory, magnetic tape, punch cards, etc.Preferably, data are stored on removable memory. For both storing andtransmitting or retransmitting data, flexible use of removable memorycan either buffer signal data or store the data for later transmission.Preferably, nonvolatile removable memory can be used to customize thesystem's buffering capacity and completely store the data.

If the data acquisition system is configured to transmit the data, theremovable memory acts as a buffer. In this situation, if the dataacquisition system loses its connection with the receiving station, thedata acquisition system will temporarily store the data in the removablememory until the connection is restored and data transmission canresume. If however the data acquisition system is configured to send alldata to the removable memory for storage, then the system does nottransmit any information at that time. In this situation, the datastored on the removable memory can be retrieved by either transmissionfrom the data acquisition system, or by removing the memory for directreading.

The method of directly reading will depend on the format of theremovable memory. Preferably the removable memory is easily removableand can be removed instantly or almost instantly without tools. Thememory is preferably in the form of a card and most preferably in theform of a small easily removable card with an imprint (or upper or lowersurface) area of less than about two sq. in. If the removable memory isbeing used for data storage, preferably it can write data as fast as itis produced by the system, and it possesses enough memory capacity forthe duration of the test. These demands will obviously depend on thetype of test being conducted, tests requiring more sensors, highersampling rates, and longer duration of testing will require faster writespeeds and larger data capacity. The type of removable memory used canbe almost any type that meets the needs of the test being applied. Someexamples of the possible types of memory that could be used include butare not limited to Flash Memory such as CompactFlash, SmartMedia,Miniature Card, SD/MMC, Memory Stick, or xD-Picture Card. Alternatively,a portable hard drive, CD-RW burner, DVD-RW burner or other data storageperipheral could be used. Preferably, a SD/MMC—flash memory card is useddue to its small size. A PCMCIA card is least preferable because of thesize and weight.

When the data acquisition system is programmed to retransmit the signalsfrom the sensors, preferably the data acquisition system transmits thesignals to a processor for analysis. More preferably, the dataacquisition system immediately retransmits the signals to a processorfor analysis. Optionally, the data acquisition system receives thesignals from one or more of the aforementioned sensors and stores thesignals for later transmission and analysis. Optionally, the dataacquisition system both stores the signals and immediately retransmitsthe signals.

When the data acquisition system is programmed to retransmit the signalsfrom the sensors or transmit a signal based at least in part on thesignal from the sensors (collectively “to transmit” in this section),the data acquisition system can transmit through either a wirelesssystem, a tethered system, or some combination thereof. When the systemis configured to transmit data, preferably the data transmission steputilizes a two-way (bi-directional) data transmission. Using two-waydata transmission significantly increases data integrity. Bytransmitting redundant information, the receiver (the processor,monitoring station, or the like) can recognize errors and request arenewed transmission of the data. In the presence of excessivetransmission problems, such as transmission over excessive distances orobstacles absorbing the signals, the data acquisition system can controlthe data transmission or independently manipulate the data. With controlof data transmission it is also possible to control or re-set theparameters of the system, e.g., changing the transmission channel orencryption scheme. For example, if the signal transmitted issuperimposed by other sources of interference, the receiving componentcould secure a flawless transmission by changing the channel. Anotherexample would be if the transmitted signal is too weak, the receivingcomponent could transmit a command to increase the transmitting power.Still another example would be for the receiving component to change thedata format of the transmission, e.g., in order to increase theredundant information in the data flow. Increased redundancy allowseasier detection and correction of transmission errors. In this way,safe data transmissions are possible even with the poorest transmissionqualities. This technique opens a simple way to reduce the transmissionpower requirements, thereby reducing the energy requirements andproviding longer battery life. Another advantage of a bi-directionaldigital data transmission lies in the possibility of transmitting testcodes in order to filter out external interferences, for example,refraction or scatter from the transmission current. In this way, it ispossible to reconstruct falsely transmitted data.

All of the preferable embodiments of this method employ a wireless dataacquisition system. This wireless data acquisition system consists ofseveral components, each wirelessly connected. Data is collected fromthe sensors described above by a patient interface box. The patientinterface box then wirelessly transmits the data to a separate signalpre-processing module, which then wirelessly transmits the pre-processedsignal to a receiver. Alternatively, the patient interface box processesthe signal and then directly transmits the processed signal directly tothe receiver using wireless technology. Further alternatively, thepatient interface box wirelessly transmits the signals to the receiver,which then pre-processes the signal. Preferably, the wireless technologyused by the data acquisition system components is radio frequency based.Most preferably, the wireless technology is digital radio frequencybased. The signals from the sensors and/or the pre-processed signals aretransmitted wirelessly to a receiver, which can be a base station, atransceiver hooked to a computer, a personal digital assistant (PDA), acellular phone, a wireless network, or the like. Most preferably, thephysiological signals are transmitted wirelessly in digital format to areceiver.

Wireless signals between the wireless data acquisition system componentsare both received and transmitted via frequencies preferably less thanabout 2.0 GHz. More preferably, the frequencies are primarily 902-928MHz, but Wireless Medical Telemetry Bands (WMTS), 608-614 MHz, 1395-1400MHz, or 1429-1432 MHz can also be used. The present invention may alsouse other less preferable frequencies above 2.0 GHz for datatransmission, including but not limited to such standards as Bluetooth,WiFi, IEEE 802.11, and the like.

When a component of the wireless data acquisition system is configuredto wirelessly transmit data, it is preferably capable of conducting aradio frequency (RF) sweep to detect an occupied frequency or possibleinterference. The system is capable of operating in either “manual” or“automatic” mode. In the manual mode, the system conducts an RF sweepand displays the results of the scan to the system monitor. The user ofthe system can then manually choose which frequency or channel to usefor data transmission. In automatic mode, the system conducts a RF sweepand automatically chooses which frequencies to use for datatransmission. The system also preferably employs a form of frequencyhopping to avoid interference and improve security. The system scans theRF environment then picks a channel over which to transmit based on theamount of interference occurring in the frequency range.

The receiver (base station, remote communication station, or the like)of various embodiments of the wireless data acquisition system can beany device known to receive RF transmissions used by those skilled inthe art to receive transmissions of data. By way of example but notlimitation, the receiver can include a communications device forrelaying the transmission, a communications device for re-processing thetransmission, a communications device for re-processing the transmissionthen relaying it to another remote communication station, a computerwith wireless capabilities, a PDA with wireless capabilities, aprocessor, a processor with display capabilities, and combinations ofthese devices. Optionally, the receiver can further transmit data toanother device and/or back. Further optionally, two different receiverscan be used, one for receiving transmitted data and another for sendingdata. For example, with the wireless data acquisition system used in thepresent invention, the receiver can be a wireless router thatestablishes a broadband Internet connection and transmits thephysiological signal to a remote Internet site for analysis, preferablyby the subject's physician or another clinician. Other examples of areceiver are a PDA, computer, or cell phone that receives the datatransmission, optionally re-processes the information, and re-transmitsthe information via cell towers, land phone lines, or cable to a remoteprocessor or remote monitoring site for analysis. Other examples of areceiver are a computer or processor that receives the data transmissionand displays the data or records it on some recording medium that can bedisplayed or transferred for analysis at a later time.

The preferred embodiment of secure data transmission that is compatiblewith HIPAA and HCFA guidelines will be implemented using a virtualprivate network. More preferably, the virtual private network will beimplemented using a specialized security appliance, such as the PIX506E, from Cisco Systems, Inc, capable of implementing IKE and IPSec VPNstandards using data encryption techniques such as 168-bit 3DES, 256-bitAES, and the like. Still more preferably, secure transmission will beprovided by a 3^(rd) party service provider or by the healthcarefacility's information technology department. The system will offerconfiguration management facilities to allow it to adapt to changingguidelines for protecting patient health information (PHI).

Preferably, the data acquisition system retransmits the signals from thesensors applied to the subject or transmits a signal based at least inpart on at least one of the physiological, kinetic, or environmentalsignals at substantially a same time as the signal is received orgenerated. At substantially the same time preferably means withinapproximately one hour. More preferably, at substantially the same timemeans within thirty minutes. Still more preferably, at substantially thesame time means within ten minutes. Still more preferably, atsubstantially the same time means within approximately one minute. Stillmore preferably, at substantially the same time means withinmilliseconds of when the signal is received or generated. Mostpreferably, a substantially same time means that the signal istransmitted or retransmitted at a nearly instantaneous time as it isreceived or generated. Transmitting or retransmitting the signal atsubstantially a same time allows the physician or monitoring service toreview the subject's physiological and kinetic signals and theenvironmental signals and if necessary to make a determination, whichcould include modifying the patient's treatment protocols or asking thesubject to adjust the sensors.

Various embodiments of the present invention include a step ofmonitoring a patient from a separate monitoring location. Datatransmitted in a remote monitoring application may include, but are notlimited to, physiological data, kinetic data, environmental data, audio,and/or video recording. It is preferable that both audio and videocommunications be components of the envisioned system in order toprovide interaction between patient and caregiver when desired.

The envisioned remote monitoring step will require data processing,storage, and transmission. This step may be completed or accomplished inone or more modules of the data acquisition system. The preferredembodiment realizes the remote system as two separate components with apatient interface module that can collect, digitize, store, and transmitdata to a base station module that can store, process, compress,encrypt, and transmit data to a remote monitoring location.

Signal quality of the signals from all the sensors can be affected bythe posture and movement of the subject. Therefore, the inventionpreferably incorporates a step to more completely remove motion andother artifacts by firmware and/or software correction that utilizesinformation collected preferably from a sensor or device to detect bodymotion, and more preferably from an accelerometer.

Turning now to a description of the figures, FIG. 1 shows a schematicdiagram of a subject using one embodiment of the present invention. InFIG. 1, a data acquisition device 208 receives signals from varioussensors placed on the subject 200, 201, 202, 204. These sensors can bebiometric sensors 200, respiratory sensors 201, ECG sensors 202, EEGsensors 204 or any of the other sensors described herein or known in theart. Although only four types of sensors are shown, the data acquisitiondevice is capable of accepting input signals from multiple additionalsensors or using as few as two sensors. The data acquisition device canstore the data received from the sensors, transmit the data to a remotelocation, or both. In this case, data is transmitted via wireless signal206 to a base station 212 which receives the signal 206 and transfersthe data to an external programming and analysis device 216, shown hereas a notebook computer, via a data interface cable 214. The externalprogramming and analysis device 216 can then further transmit sleep datato a remote location using the internet or other communication means(not shown).

FIG. 2 is a schematic of one embodiment of the data acquisition deviceand system of the present invention. In FIG. 2, a data acquisitionsystem (similar to that shown in FIG. 3) is used to receive, filter, andoptionally analyze signals from sensors (not shown) on a subject (notshown). The data acquisition system (shown in FIG. 3) transmits a signalbased, at least in part, on one or more of the signals from the sensorson the subject. The data acquisition device and system transmits thesignal 55 from the subject's home 86, a hospital 87, or even a mobileremote location such as a sleeper of a semi-trailer truck 84 to a server70 for analysis. The signal is transmitted over the internet or othercommunication system 58. The signal 55 that is transmitted over theinternet or other communication system 58 can be compressed to providebetter resolution or greater efficiency. The server 70 in thisembodiment may also perform data analysis (not shown). The analyzed data73 is then entered into a database 76. The analyzed data 73 in thedatabase 76 can then be requested 79 and sent 63 to review stations 82anywhere in the world via the internet or other communication system 58for further analysis and review by clinicians, technicians, researchers,physicians and the like. The communications systems used for datatransmission need not be the same at all stages. For example, a cellularnetwork can be used to transmit data between the subject's home 86 andthe remote analysis server 70. The internet can then be used to transmitdata between the remote analysis server 70 and the database 76. Finallyin this example, a LAN could be used to transmit data between thedatabase 76 and a review station 82.

FIG. 3 is a block diagram showing the data flow through the dataacquisition system 350 used in certain embodiments of the presentinvention. In this embodiment, various sensors generate physiologicalsignals 322, kinetic signals 324, environmental signals 326, andbiometric signals 328. The sensor signals 330 are input into the dataacquisition system 350, consisting of (a) a data acquisition device 208containing a sensor interface module 336, a preprocessor module 338, atransceiver module 340, a data storage module 341, and a power module334, and (b) a base station 212 containing a storage module 348, asecond pre-processor module 346, and a communication module 344.Typically, the data acquisition device 208 is worn by the subject duringthe test period. For portability of the data acquisition device 208, thepower module 334 can be battery-powered. The data acquisition device 208sends data via wireless signal 206 to the base station 212. The basestation 212 uses the communication module 344 to retransmit the signalsfrom the sensors 330 and/or transmit signals based at least in part onat least one of the signals to remote stations (not shown). Optionally,all sensor signals 330 could be channeled directly into the data storagemodule 341 of the data acquisition device 208 and saved for download andanalysis at a later time, eliminating the need for wireless transmissionof data 206 to the base station 212. Further optionally, all sensorsignals 330 could be directed into the data storage module 341 and savedfor later download while simultaneously being transmitted to a remotestation (not shown) via wireless communication 206 with the base station212. Although transmission between the data acquisition device 208 andthe base station 212 is shown in FIG. 3 as wireless 206, the connectioncould also be a wired connection in other embodiments of the dataacquisition system.

FIG. 4 is a signal flow diagram showing the flow of biometric data inone embodiment of the present invention. In this embodiment, a biometricsensing device 200 is used to collect and record biometric data andsubsequently verify subject identity during the course of a sleep test.In a preferred embodiment, biometric data is collected using a biometricsensor 101 then processed and stored 102 within the biometric sensingdevice 200. When a subject's identity is verified against the previouslycollected biometric data during a sleep test, a simple pass/fail result106 preferably, but not necessarily is output by the biometric sensingdevice 200 and communicated 108 to the data acquisition device 208 whilethe biometric identification data itself may remain stored 102 on thebiometric sensing device 200. The pass/fail result output 106 by thebiometric sensing device 200 may be stored in the data acquisitiondevice 208, wirelessly transmitted to a remote station 206, 212 or acombination of both. In an optional embodiment of the present invention,the biometric sensing device 200 may consist of only a biometric sensor101 which is capable of capturing biometric data for export to the dataacquisition device 208 where it is stored, processed, and subsequentlyused for subject identification. Although transmission between the dataacquisition device 208 and the base station 212 is shown in FIG. 4 aswireless 206, the connection could also be a wired connection in otherembodiments of the present invention.

FIG. 5 is a flow chart of one embodiment of the method for using abiometric sensor or sensors to verify a subject's identity during asleep analysis procedure. Prior to beginning sleep analysis testing, abiometric characteristic or parameter is collected and recorded at theoffice of the subject's physician or collected from some other reliable,preexisting source 62. Once recorded, this parameter is used by thebiometric sensor to verify the subject's identity during the course ofthe sleep analysis procedure. The biometric sensor is then applied tothe subject 64 either by the physician, technician or the like while atthe physician's office or by the subject himself at a later time butprior to beginning the sleep analysis test. Either before or after(after shown here) application of the biometric sensor to the subject,the biometric sensor is connected to a data acquisition system 66. Oncethe biometric sensor and other desired sensors are connected to the dataacquisition system, the sleep test can be started when the subjectattempts to sleep 68. After starting the sleep test, data collectionbegins and the biometric sensor verifies subject identity continuously,randomly, or periodically for the duration of the test 70. If at anytime during the sleep test the biometric sensor is unable to positivelyverify the identity of the test subject against the previously recordedbiometric data for a prespecified successive number of attempts, thesubject is alerted and/or the sleep analysis test is stopped 72, 74. Ifsubject identity is positively verified, data is recorded and/ortransmitted as normal 72, 76. Based on the collected and/or transmitteddata a sleep analysis is performed and the subject is diagnosed 78.

FIGS. 6A-D show various preferred embodiments of a biometric sensingdevice, more specifically a fingerprint sensor, used in the presentinvention to verify subject identity during the course of sleep analysisand, optionally, to collect biometric data. It is important to note thatin each embodiment shown in FIGS. 6A-D, a pulse oximeter is used incombination with a biometric sensing device in such a way that the pulseoximeter is worn on the same hand as the biometric sensing device. Asalready noted, this serves to ensure that the individual for whom sleepdata is being recorded is in fact the individual from whom pulseoximetry data is collected and for whom sleep analysis was intended.

In one embodiment, shown in FIG. 6A and FIG. 6B, a pulse oximeter isused in combination with a biometric sensing device in such a way thatbiometric verification of subject identity and pulse oximetry areperformed on the same digit or finger 540. FIG. 6A provides across-sectional view of this embodiment showing a fingerprint sensor 542positioned to read a subject's fingerprint and a pulse oximeterpositioned to collect data from the same digit 544. FIG. 6B provides aperspective view of this embodiment 540 as it could be used on the handof an individual subject. It should be noted that although thisembodiment is shown as being used on a subject's index finger 546, it isnot limited to use on this digit and could be used on any other desireddigit of the hand. Further, it is envisioned that this embodiment wouldallow biometric verification and pulse oximetry measurements to occur onthe same digit simultaneously or in an alternating fashion.

In another embodiment, shown in FIG. 6C, a biometric sensing device andpulse oximeter are used in a shared finger-gripping device 550 in such away that pulse oximetry and biometric verification must occur on twoadjacent digits of the same hand. In this embodiment, it isinsignificant on which digit biometric verification of identity occursand on which digit pulse oximetry occurs. Communication with the dataacquisition device in this embodiment is performed through a singleconnection 552.

In still another embodiment, shown in FIG. 6D pulse oximetry andbiometric verification of identity are performed on separate, optionallynon-adjacent digits. In this embodiment, the pulse oximeter 564 islinked to the biometric sensing device 200 by a shared communicationconnection 560 to the data acquisition device (not shown) in such a wayas to require that both devices be used on the same hand. Although inthis embodiment the biometric sensing device 200 is linked to the pulseoximeter 564 by a shared communication connection 560 to the dataacquisition device (not shown) it is envisioned that various other meanscould be used to physically link the two devices. For example, thedevices need not use a shared communication connection 560 and maycommunicate with the data acquisition device (not shown) using separate,individual channels. In this case, the two devices could be linkedthrough a different type of physical connection such as a short lengthof braided polymer or other similar material. Data collected and/ortransmitted using any of the various embodiments shown in FIGS. 6A-D,could be transmitted to the data acquisition device (not shown) using ashared, single channel or any combination of multiple channels.

FIG. 7 is a flow diagram showing one embodiment of the method andprocess of the present invention. In this embodiment, a trucking companyor similar entity desires sleep testing or sleep screening for one ormore employees 400. In this embodiment, a single employee truck driveris chosen for sleep screening 400 and subsequently referred to anon-site nurse's office 402. The nurse's office is represented by box404. After arrival at the nurse's office 406 the employee receivesinstruction on proper use and application of the sleep analysis system408. Preferably, this instruction includes printed guides outliningproper use of the system for future reference and review by theemployee. Optionally, this instruction could include multimediareferences such as instructional digital versatile discs, or the like.After instruction on proper use, employee biometric data is collectedand recorded 410 for use in verification of identity during remote sleeptesting. Collection of biometric data is preferably performed using thebiometric sensing device (shown in FIG. 4). Proper function of thebiometric identification step (not shown) is also preferably verified atthe time of biometric data collection 410. The employee then leaves thenurse's office carrying the sleep analysis system 412, in this case,comprised of a multi-channel data acquisition device and the propersensors. In the present embodiment the employee would then return towork and begin a multi-day driving assignment 414. In this case, theemployee stops to sleep while still en route to his or her finaldestination and prepares to sleep in the sleeping area of the cab of thesemi-trailer truck 416 which he or she has been operating. Prior tosleep, the employee applies the sensors to his or her actual person andconnects the sensors to the data acquisition device 418 according to theprovided instructions 408. Sleep data is then recorded by the sleepanalysis system for a minimum of two hours of sleep 420. During thistime, the employee identity is also verified by the biometric sensingdevice (shown in FIG. 4). Upon awakening from sleep, the employeeremoves the sleep sensors and places the sensors and data acquisitiondevice in a prepaid envelope 422 for mailing to an off-site sleepanalysis station 424. This envelope is then mailed from a suitablelocation at the convenience of the employee. Upon receipt of the sleepanalysis system at an off-site sleep analysis station, the data isremoved from the data acquisition device and analyzed by a technician,clinician, physician, or the like 426 and a diagnosis is made and sentto both employer and employee 428.

FIG. 8 is a block diagram showing one envisioned method and process ofuse for one specific embodiment of the present invention. In thisembodiment, an airline or similar entity desires sleep testing or sleepscreening for one or more employees 440. Here, a single employee pilotis chosen for sleep screening 440 and subsequently scheduled to attendan in-office training meeting on proper use of sleep analysis equipment442. The training meeting is represented by box 444. After arrival atthe training meeting 446 the employee receives instruction on proper useand application of the sleep analysis system 448. Preferably, thisinstruction includes printed guides outlining proper use of the systemfor future reference and review by the employee. Optionally, thisinstruction could include multimedia references such as instructionaldigital versatile discs, or the like. After instruction on proper use ofthe sleep analysis system, employee biometric data is collected andrecorded 450 for use in verification of identity during remote sleeptesting. Collection of biometric data is preferably performed using thebiometric sensing device (shown in FIG. 4). Proper function of thebiometric identification step (not shown) is also preferably verified atthe time of biometric data collection 450. The employee then leaves thetraining meeting carrying the sleep analysis system 452, in this case,comprised of a multi-channel data acquisition device capable of wirelesscommunication, a wireless communication receiver, an externalprogramming and analysis device (e.g. a notebook computer) and theproper sleep sensors. In the present embodiment, the employee would thenreturn to work and begin a multi-day travel/flight assignment 454. Inthis case, the employee stops to sleep during the travel/flightassignment at a hotel with internet access 456 or access to anothersimilar communication system. Prior to sleep, the employee applies thesensors to his or her actual person and connects the sensors to the dataacquisition device 458 according to the provided instructions 448.Further, the employee ensures that the wireless communication betweenthe data acquisition device and the wireless receiver station isfunction properly 460 and that data transmission and communicationbetween the external programming device and remote sleep analysisstation is functioning properly 462. In a preferable embodiment,telephone or other live communication support is available for the stepsof connecting the sleep analysis system 458, 460, 462. Sleep data isthen recorded and transmitted to a remote sleep analysis station by thesleep analysis system for a minimum of two hours of sleep 464. Duringthis time, employee identity is also verified by the biometric sensingdevice (shown in FIG. 4). Upon awakening from sleep, the employeeremoves the sleep sensors and returns the sleep analysis system using aprepaid mailing package or by drop-off at any company office. The datatransmitted in 464 is analyzed either in real-time, during transmission,or at some time shortly afterward by a technician, clinician, physician,or the like and a diagnosis is made and sent to both employer andemployee 468.

Referring now to FIG. 9, there is shown a more detailed block diagram ofthe signal processing module 85 of the data acquisition device (shown inFIG. 3) with the sensor or sensors 91 and the module antenna 100. Thesignal processing module 85 comprises input means 115, analog-to-digital(A/D) means 118, a module microcontroller 121 with a nonvolatile memory,advantageously, an EEPROM 124, a module transmitter 127, a connection toremovable memory 130, a module receiver 133 and a module power supply136. Although the module antenna 100 is shown externally located fromthe signal processing module 85, it can also be incorporated therein. Amodule power supply 136 provides electrical power to the signalprocessing module 85. Additionally the signal processing module 85 willpreferably contain an accelerometer 131 connected to a microprocessor139 for position detection, motion detection, and motion artifactcorrection.

The input means 115 is adjustable either under control of the modulemicrocontroller 121 or by means of individually populatable componentsbased upon the specific external input 88 (i.e. a signal from anysensor) characteristics and range enabling the input means 115 to acceptthat specific external input 88.

After receipt by the input means 115, the external input 88 is inputtedto the A/D means 118. The A/D means 118 converts the input to a digitalsignal 142 and conditions it. The A/D means 118 utilizes at least oneprogrammable A/D converter. This programmable A/D converter may be anAD7714 as manufactured by Analog Devices or similar. Depending upon theapplication, the input means 115 may also include at least one low noisedifferential preamp. This preamp may be an INA126 as manufactured byBurr-Brown or similar. The module microcontroller 121 can be programmedto control the input means 115 and the A/D means 118 to provide specificnumber of external inputs 88, sampling rate, filtering and gain. Theseparameters are initially configured by programming the modulemicrocontroller 121 to control the input means 115 and the A/D means 118via input communications line 145 and A/D communications line 148 basedupon the input characteristics and the particular application. Ifdifferent sensors are used, the A/D converter is reconfigured byreprogramming the module microcontroller 121.

The module microcontroller 121 controls the operation of the signalprocessing module 85. In the present embodiment, the modulemicrocontroller 121 includes a serial EEPROM 124 but any nonvolatilememory (or volatile memory if the signal processing module remainspowered) can be used. The EEPROM 124 can also be a separate componentexternal to the module microcontroller 121. The module microcontrollermay advantageously contain two microprocessors in series as shown inFIG. 9. The module microcontroller 121 is programmed by the externalprogramming means (shown in FIG. 1) through the connector 172 or throughradio frequency signal from the base station (shown in FIG. 3). The samemodule microcontroller 121, therefore, can be utilized for allapplications and inputs by programming it for those applications andinputs. If the application or inputs change, the module microcontroller121 is modified by merely reprogramming. The digital signal 142 isinputted to the module microcontroller 121. The module microcontroller121 formats the digital signal 142 into a digital data stream 151encoded with the data from the digital signal 142. The digital datastream 151 is composed of data bytes corresponding to the encoded dataand additional data bytes to provide error correction and housekeepingfunctions. The digital data stream 151 is used to modulate the carrierfrequency generated by the transmitter 127.

The module transmitter 127 is under module microcontroller 121 control.The module transmitter 127 employs frequency synthesis to generate thecarrier frequency. In the preferred embodiment, this frequency synthesisis accomplished by a voltage controlled crystal reference oscillator anda voltage controlled oscillator in a phase lock loop circuit. Thedigital data stream 151 is used to frequency modulate the carrierfrequency resulting in the wireless data transmission signal 206 whichis then transmitted through the module antenna 100. The generation ofthe carrier frequency is controlled by the module microcontroller 121through programming in the EEPROM 124, making the module transmitter 127frequency agile over a broad frequency spectrum. In the United Statesand Canada a preferred operating band for the carrier frequency is 902to 928 MHz. The EEPROM 124 can be programmed such that the modulemicrocontroller 121 can instruct the module transmitter 127 to generatea carrier frequency in increments between 902 to 928 MHz. as small asabout 5 to 10 kHz. In the US and other countries of the world, thecarrier frequency may be in the 902-928 MHz, Wireless Medical TelemetryBands (WMTS), 608-614 MHz, 1395-1400 MHz, or 1429-1432 MHz or otherauthorized band. This allows the system to be usable in non-NorthAmerican applications and provides additional flexibility.

The voltage controlled crystal oscillator (not shown) in the moduletransmitter 127, not only provides the reference frequency for themodule transmitter 127 but, advantageously also provides the clockfunction 154 for the module microcontroller 121 and the A/D means 118assuring that all components of the signal processing module 85 aresynchronized. An alternate design can use a plurality of referencefrequency sources where this arrangement can provide certain advantagessuch as size or power consumption in the implementation. The modulereceiver 133 in the signal processing module 85 receives RF signals fromthe base station (shown in FIG. 3). The signals from the base stationcan be used to operate and control the signal processing module 85 byprogramming and reprogramming the module microprocessor 121 and EEPROM124 therein.

Optionally, the signal processing module 85 of the data acquisitiondevice (shown in FIG. 3) may include an output means (not shown). Forexample, the processor 139 may have a connection to an output meansthrough which processed digital information could be passed to anexternal device, such as a fingerprint sensing device, in order tomodulate the function of the external device. In another embodiment,digital information may pass first through the A/D converter 118 and beconverted to analog format prior to being sent via the output means toan external analog device.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the present inventionwithout departing from the spirit and scope of the invention. Thus, itis intended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

I claim:
 1. A remote or home sleep diagnostic system comprising a deviceand a database, the database remote from a test location, for anunattended sleep test, the system adapted for providing sleep test datafrom the database for analysis and diagnosing sleep apnea, the devicefurther comprising a portable, wearable patient interface box with atleast three sensors for measuring physiological parameters of a subjectrelated to the subject's quality of sleep, the at least three sensorsbeing an air flow or snore sensor, a pulse oximeter sensor and arespiratory effort sensor, a processor and at least one biometric sensorfor identifying the subject, wherein the portable, wearable interfacebox houses the processor having circuitry adapted to connect the atleast three sensors and the biometric sensor to the processor to collectdata for identification of the subject being tested using the data fromthe biometric sensor, the at least one biometric sensor is adapted torandomly collect data to authenticate the identity of the subject beingtested during a sleep test, and the collected data is uploaded from theportable, wearable patient interface box to the database for furtheroutput in a form for analysis and diagnosis by a clinician.
 2. Thesystem of claim 1, wherein the processor or another processor is adaptedto use previously collected biometric data of the subject to verify thesubject's identity who took the sleep test.
 3. The system of claim 1wherein the system is adapted to compare the collected biometric datawith previously collected biometric data, and is adapted to securelyexchange information to comply with HIPAA requirements with an externaldevice through a transceiver on the system.
 4. The system of claim 1,wherein the at least one biometric sensor is adapted to collectbiometric data from a subject, the processor or another processor isadapted to compare the collected biometric data previously collectedfrom the subject, and the processor or the another processor is adaptedto output verification of the identity of the subject whose quality ofsleep is being measured without outputting the subject's biometric data.5. The system of claim 1 wherein the at least one biometric sensor isselected from the group of sensors consisting of fingerprint sensors,facial recognition sensors, hand geometry sensors, iris and retinalsensors, and voice recognition sensors.
 6. The system of claim 1 furtherincluding a transceiver or transmitter adapted to transmit the data fromthe at least one biometric sensor and/or the at least three sensors tothe database at remote location.
 7. The system of claim 1, wherein thebiometric sensor is a fingerprint sensor.
 8. A remote or home sleepdiagnostic system comprising a device and a database, the databaseremote from a test location, for an unattended sleep test, the systemadapted for providing sleep test data from the database for analysis anddiagnosing sleep apnea, the device further comprising an portable,wearable patient interface box with at least three sensors for measuringphysiological parameters of a subject related to the subject's qualityof sleep, the at least three sensors being an air flow or snore sensor,a blood oxygenation sensor and a respiratory effort sensor, a processorand at least one biometric sensor for identifying the subject whereinthe portable, wearable patient interface box houses the processor havingcircuitry adapted to connect the at least three sensors and thebiometric sensor to the processor, to collect data for identification ofthe subject being tested using the data from the biometric sensor tocompare with biometric data previously collected from the subject, andto upload the collected data from the portable, wearable patientinterface box to the database for further output in a form for analysisand diagnosis by a clinician.
 9. The system of claim 8, whereinauthentication of subject identity by said biometric sensor is performedrandomly.
 10. The system of claim 8, wherein the system is adapted touse previously collected biometric data of the subject to verify thesubject identity with the processor during the course of the sleep test.11. The system of claim 8, wherein the system is adapted to compare thecollected biometric data with previously collected biometric data, andis adapted to securely exchange information to comply with HIPAArequirements with an external device through a transceiver on thesystem.
 12. The system of claim 8, wherein the biometric sensor isadapted to detect a biometric electrophysiological characteristic of thesubject.
 13. The system of claim 8, the system further comprising amemory for storing biometric data of the subject for comparison.
 14. Thesystem of claim 8 wherein the at least one biometric sensor is selectedfrom the group of sensors consisting of fingerprint sensors, facialrecognition sensors, hand geometry sensors, iris and retinal sensors,and voice recognition sensors.
 15. A remote or home sleep diagnosticsystem comprising a device and a database, the database remote from atest location, for an unattended sleep test, the system adapted forproviding sleep test data for analysis and diagnosing sleep apnea, thedevice further comprising a portable, wearable patient interface boxwith at least three sensors for measuring physiological parameters of asubject related to the subject's quality of sleep, the at least threesensors being an air flow or snore sensor, a blood oxygenation sensorand a respiratory effort sensor, a processor and at least one biometricsensor for identifying the subject wherein the biometric sensor isadapted to detect a biometric electrophysiological characteristic of thesubject and the portable, wearable patient interface box houses theprocessor having circuitry adapted to connect the at least three sensorsand the biometric sensor to the processor, to collect data foridentification of the subject being tested using the data from thebiometric sensor to compare with biometric data previously collectedfrom the subject, and to upload the collected data from the portable,wearable patient interface box to the database for further output in aform for analysis and diagnosis by a clinician.
 16. The system of claim15, wherein authentication of subject identity by said biometric sensoris performed randomly.
 17. The system of claim 15 wherein the at leastone biometric sensor is selected from the group of sensors consisting offingerprint sensors, facial recognition sensors, hand geometry sensors,iris and retinal sensors, and voice recognition sensors.
 18. The systemof claim 15, compares the collected biometric data with the biometricdata previously collected from the subject, and the processor outputsverification of the identity of the subject whose quality of sleep isbeing measured without outputting the subject's biometric data.
 19. Thesystem of claim 18, wherein biometric data is loaded onto the sleepdiagnostic device from an already existent source.
 20. The system ofclaim 15, wherein the biometric sensor is a EKG sensor.